Wire antenna extensible along calibrated support means



Sept. 1968 o. c. GALLAGHER ETAL 3,

WIRE ANTENNA EXTENSIBLE ALONG CALIBRATED SUPPORT MEANS Filed March 12,1965 2 Sheets-Sheet 1 INVENTORS DONALD C. GALLAGHER LESTER W. HAERTHERJOHN A. MIDDLETON EDWARD G. TUTHILL ATTOR EYS Se t. 3, 1968 D. c.GALLAGHER ETAL 3,

WIRE ANTENNA EXTENSIBLE ALONG CALIBRA'I'ED SUPPORT MEANS Filed March 12,1965 2 Sheets-Sheet 2 INVENTORS QONALD C. GALLAGHER LESTER W HAERTHERJOHN A. MIDDLETON E WARD TUTHILL ATTO E s United States Patent 3,400,402WIRE ANTENNA EXTENSIBLE ALONG CALIBRATED SUPPORT MEANS Donald C.Gallagher, Marion, Lester W. Haerther, Cedar Rapids, and John A.Middleton and Edward G. Tuthill, Marion, Iowa, assignors to CollinsRadio Company, Cedar Rapids, Iowa, a corporation of Iowa Filed Mar. 12,1965, Ser. No. 439,235 2 Claims. (Cl. 343723) ABSTRACT OF THE DISCLOSUREA wire antenna system dependent in part on terrain features orstructures such as existing trees or buildings for antenna support, andutilizing electrically nonconductive glassline cord with spacedfrequency markings with relatively light wire as an antenna radiationelement strung therealong and supported by the cord. Further, in a shortwire version a plurality of counterpoise wires with spaced frequencymarkings are unreeled to desired frequency tuned lengths in diversedirections along the ground and with the partially unreeled reel endsleft laying on the ground in their extended diverse positions.

This invention relates in general to field antenna systems, and inparticular, to an antenna system capable of quick, easy erection in thefield as a simple, lightweight, and rugged quarter-wave short wireantenna or a halfwave doublet antenna when there is sufficient time andfacility therefor.

Prospecting teams, exploration parties, surveying teams, and themilitary utilize various field antenna systems in meeting variouscommunication operational requirements. Obviously, weight as well ascomplexity-of various antenna systems can be a problem in fieldoperations. Furthermore, field use requirements impose stringent factorsof ruggedness and reliability, in operation for successfully meetingfieldv operational requirements. Cost also becomes a significant factorwheremany antennas are likely to be used in the field and/or wherevarious antennas are likely to be left in place for future use orabandoned in location after use.

. It is, therefore, a principal object of this invention to provide asmall and lightweight antenna equipment kit that lends itself to quickand easy erection of a short wire quarter-wave antenna primarily forground wave propagation and for some long sky-wave propagation, and theerection of a half-wave doublet field antenna using some componentscommon to both antennas when a little more time is available for antennaerection and the primary use is to be for sky-wave propagation over longdistances.

Another object is to provide an antenna structure utiliziug glasslineantenna supporting cord equipped with A mc. frequency markings startingfrom the free end of cord reels, and small diameter light antenna wireadjustably unrolled from reels along frequency marked glassline cord forapproximate frequency length matched antenna turned settings.

Featuresof this invention useful in accomplishing the above objectsinclude, in a lightweight antenna equipped erection kit for alternateerection of a short wire quarterwave wire antenna and ahalf-wave'doublet field antenna, reels of electrically nonconductiveglassline cord having A mc. frequency markings starting from each reelfree end, two of which are utilized in the erection of the halfwavedoublet field antenna and one of which is used in erecting the shortwire quarter-wave antenna. Two small reels of relatively lightlusterless copperweld wire are also included in the kit, two being usedas antenna wires with the half-wave doublet field antenna and only onebeing used with the short wire quarter-wave antenna, and with, in eachinstance, the antenna wire being unreeled along the frequency markedglassline cord to desired frequency tuned lengths from shorthigh-frequency lengths to longer low-frequency lengths. Three reels ofcovered and frequency marked copperweld wire are also included for useas counterpoised wires for the short wire quarter-Wave antenna with thefrequency markings of the counterpoise wires facilitating unreeling ofthese wires to approximately the desired frequency tuned lengths of theantenna in divergent directions along the ground. Equipment of theantenna erection kit useful in one and/ or the other of the antennasalso includes a weatherproof antenna feed plate, a length of coaxconductor, a tie down stake and an additional supply of ground stakes,and casting weights for the throwing of antenna support ing glasslinecord over an elevated supporting feature of the environment, forexample, the branch of a tree.

Specific embodiments representing what are presently regarded as thebest modes of carrying out the invention are illustrated in theaccompanying drawings.

In the drawings:

FIGURE 1 represents a side view of a half-wave doublet field antennainstallation;

FIGURE 2, a perspective view of a short wire quarterwave antennainstallation;

FIGURE 3, a partial view of a glassline reel as fastened down with aground stake and with glassline cord extended therefrom for use in anantenna installation;

FIGURE 4, a crank face view of the glassline cord reel of FIGURE 3;

FIGURE 5, a view of an antenna reel as mounted in place on a glasslinecord;

FIGURE 6, a side view of the antenna reel of FIG- URE 5 with antennawire and antenna reel positioned at a tuned frequency length on aglassline cord; and,

FIGURE 7, a center interconnection feed plate of the half-wave doubletfield antenna.

Referring to the drawings:

The half-wave doublet field antenna 10 of FIGURE 1 is used primarily forskywave radio frequency wave propagation over long distances. Radiationefficiency of this antenna 10 is very good where it can be erected overheights of 30 feet even though radiation from the antenna will bepartially vertically polarized since a balun is not used at the antennafeed point in the interest of saving weight, simplicity, and reliabilityin the field. However, the slight loss in the horizontally polarizedradiated signal, as required by a partially vertically polarizedemission, does not justify the extra weight and complication incumbentwith inclusion of a balun for field use.

With erection of the half-wave doublet antenna 10 to heights of over 30feet two separate glassline cords 11 unrolled from reels 12 are thrownover relatively high limbs of appropriately spaced trees 13. This isaccomplished with casting weights (not shown) fastened to the free endsof glassline cord 11 unraveled from the respective reels 12 for suchcasting purposes over high tree limbs. The feed ends of the glasslinecords 11 are fastened (as shown in FIGURE 7) by clasps 14 to oppositeends of center interconnection feed plate 15. Two antenna reels 16(refer also to FIGURES 5 and 6) are used with the half-wave doubletfield antenna 10 with the free ends of the two antenna wires 17 fastenedto center feed terminals 18 of the center feed plate 15. The antennawires 17 of reels 16 are unrolled along the respective glassline cords11 to the desired quarter-wave frequency tuned lengths, as gauged byfrequency markings 19 in each respective direction along the glasslinecords 11 and fastened in place on the cords 11 as by reel clasps 20, andthe two quarter-wave lengths of antenna wire 17 together provide thehalf-wave doublet field antenna 10 lengths.

With increasing antenna lower frequency lengths tape wrappings 21 may beemployed at reasonable spacings along the glassline cords 11 to supportthe relatively fine light antenna wire 17 on the cords 11.

A coaxial conductor feed line 22 may be fastened to the antennainput-output connection of the receivertransmitter unit 23 and theantenna feed plate 15. A strain relief cord 24 is extended from theantenna feed plate to a fastening clamp 25 on the coax feed cable 22,which may be, for example, a 40 foot length of polyfoam filled coaxialconductor line, in order that a free nonweighted coaxial line loop 26may be provided for nonweighted connections between the coaxial feedline and the antenna feed plate 15.

The glassline reels 12 have, in the interim, been anchored to the groundin appropriate locations by ground stakes 27 driven into the groundthrough anchor extensions 28 of the respective glassline reels 12.Referring also to FIGURES 3 and 4, slack is removed from the antennaassembly by rewinding glassline cord 11 onto reels 12 by manuallyrotating the crank arms 29 until the glassline cord is taut to thedesired degree, and then locking the reel in position by spring loadedlocking clasps 30 which are devised to engage and lock with variousgrooves 31 around the parameter of flanges of the reels 12.

This provides a half-wave doublet field antenna useful primarily forsky-wave propagation over long distances, the radiation efficiency ofwhich is very good when it is erected to heights over 30 feet. Thetransmitter 23 output circuits are normally capable of tuning therelatively low VSWR impedance presented by the antenna system. With thetransmitter-receiver operating in the receive mode it generally operatesat optimum impedances with the halfwave doublet field antenna.

Please refer to the short wire quarter-wave antenna 10' installation ofFIGURE 2 for an antenna utilizing many components of an antenna erectionkit common to corresponding components used in the erection of thehalfwave doublet field antenna 10 of FIGURE 1 with correspondingcomponents numbered the same as a matter of convenience. In this antennathe free end of a glassline cord 11 from a glassline reel 12 is castover a suitable elevated support, a branch of a tree for example, andthe free end is attached to a support stake 32 driven into the ground atan appropriate distance from the suitable elevated support. The free endof an antenna wire 17 from an antenna reel 16 is fastened to theinput-output terminal of receiver-transmitter 23 located closelyadjacent the ground stake 32. The reel 16 is next unreeled to thedesired frequency length as indicated by the frequency markings on theglassline cord 11 and then the antenna reel 16 is clipped to theglassline cord 11, as illustrated in FIGURE 5 and as describedhereinbefore with respect to the embodiment of FIGURE 1. The slack fromthe antenna assembly 10 may then be removed to the desired degree oftautness by rewinding and locking the glassline reel 12 in the rewoundposition, as has been described with respect to the embodiment of FIGURE1 and as illustrated in FIGURES 3 and 4. The free ends of, preferably,at least 3 counterpoise wires 33 are connected to the support stake 32and the wires are unreeled in divergent directions to lengthsapproximating the selected frequency determined length of antenna wire17, or more. This is facilitated with the aid of mo. frequency markings34 on the covering of counterpoise wires 33 of counterpoise wire reels35, and the wires 33 and the reels 35 are left laying in the divergentextended positions on the ground.

The short wire antenna 10' of FIGURE 2 is used primarily for ground waveRF signal propagation to approximately 25 mile distances and, to someextent, for long sky-wave propagation when there is insufficient time orfield facility for erection of a doublet antenna 10 of FIG- URE 1. Theshort wire antenna with counterpoise, as shown in FIGURE 2, is found tohave an RF radiation efficiency of approximately and is quite capable ofproviding reliable 24 hour communication in a Single Sideband (SSB) modeof operation when the equipment is used over poor ground, in jungle, andin desert terrain. It should be noted that the frequency markings 19 onthe glassline antenna support cords 11 are optimized for free spaceelectromagnetic wave signal propagation conditions, and as such, thedoublet and the short wire antenna systems will not be perfectlyresonant in many situations. However, the tuning range of thetransmitter output network of the receiver-transmitter 23 will generallytune and load to the variations in impedances for the typical fieldvariations encountered. Actually, operation of the receiver-transmitter23 in the receive mode generally pro vides operation under nearlyoptimum conditions with applicants antennas.

Whereas, this invention is here illustrated and described with respectto specific embodiments thereof, it should be realized that variouschanges may be made without departing from the essential contribution tothe art made by the teachings hereof.

We claim:

1. In a field wire antenna system, an electrically nonconductive antennasupporting cord equipped with frequency markings at predeterminedfrequency spacings from a first end of the cord the other end of whichis an anchor end; radio frequency utilizing means; cord end connectiveand support means to which said first end of the cord is connected withthe cord having been cast over an elevated structural support; meansanchoring the anchor end of said nonconductive cord; antenna feed signalconnective means connected to said R-F utilizing means; antenna wiremeans connected to said antenna feed means and extendable along saidnonconductive cord from adjacent said first end of the cord to apredetermined desired frequency length as facilitated by the frequencymarkings on the nonconductive cord; means mounting said antenna wire onsaid nonconductive cord; wherein the antenna is a short wire antenna,useful for ground wave electromagnetic signal propagation to moderatedistances, and to some extent, for long sky-wave electromagnetic signalpropagation, with said cord end connective and support means being aground stake driven into the ground; said antenna wire means being asingle antenna wire connected to said antenna feed means and extendablealong the nonconductive cord to a predetermined desired frequencylength; with the antenna feed means being a feed terminal of said R-Futilizing means with the R-F utilizing means placed in position on theground adjacent said ground stake; counterpoise wires with predeterminedfrequency spacing markings from common ends attached to said groundstake with said wires being extendable over and laying along groundsurface in diverse directions from said ground stake and with thesecounterpoise wires being unreeled from counterpoise wire reels that areunreeled and left laying on the ground in their extended diversepositions.

2. The short wire antenna system of claim 1, wherein said short wireantenna system includes at least three counterpoise wires with frequencymarkings spaced from adjacent ends connected to said ground stake withthe counterpoise wires extending in diverse directions over the groundto approximately the frequency selected length of said antenna wirealong said nonconductive cord, or to a greater length.

References Cited UNITED STATES PATENTS 1,438,290 12/1922 Beakes 343877XR 1,895,493 l/l933 Sherman 343-877 2,569,810 10/1951 Hamel et al.343823 2,778,017 1/1957 Dorcsjak 343823 3,025,524 3/1962 Thies 343823(Other references on following page) 5 6 UNITED STATES PATENTS DoubletAntenna System Model TD1, Hy-Gain Antenna 3,189,906 6/1965 Kulik et aL34 710 Products, Lincoln, Nebr., IEEE Convention, Mar. 25, 3,271,7749/1966 t' 343891XR 1963- 3 The Antenna BOOk, eighth edition (second3308470 3/1967 Ben 343 886 XR 5 printing), The American Radio RelayLeague Inc., West Hartford, Conn, copyright 1956, TK6565A6, pp. 190-FOREIGN PATENTS 191 r 525,571 5/1931 Germany. 0 793 5 1951 GermanyHERMAN KARL SAALBACH, Primary Examiner.

OTHER REFERENCES 10 M. NUSSBAUM, Assistant Examiner.

Technical Data Report, The Hy-Gain Reel Tape

